|Title||Ligre Tempesta di Cieli|
|Attribute||Sky and Storm|
|Manga Debut||Chapter 225|
|Anime Debut||Episode 139|
The Sky Storm Liger is a super-rare Box Weapon that possesses the special traits of both the Sky-attribute Leone di Cieli and the Storm-attribute Tigre Tempesta. However, it is speculated that this Box Weapon was originally the "white Sky Lion", while the Ligre Tempesta di Cieli is thought to be its mutated figure caused by Xanxus mixing in the Flames of different attribute that he can emit due his unique constitution when injecting Flames in the Box. Xanxus calls it "Bester".
Similar to the Sky Lion, there are many parts about its abilities that are unknown. What is for sure is that its Flames possess simultaneously the characteristics of both the Sky and Storm Flames. Also, just like how the scars of the wounds caused by the 9th are revealed on Xanxus' body when he is mad, the Sky Storm Liger also has its own "Rage Mode" in which tiger stripes appears on its body.
- Ruggito di Cieli - The signature move of the Sky Lion, a Flame-based attack in the form of a roar. The one used by Bester is somewhat different due its Flames of multiple attributes. After the Harmony of the Sky is done petrifying the opponent on the battlefield, their body will be destroyed by the Storm's Disintegration factor.